An Ultrasound examination, also called sonography or diagnostic medical sonography is an imaging method that uses high-frequency sound waves to produce precise images of structures within your body. The images produced during an ultrasound examination often provide information that’s valuable in diagnosing and treating a variety of diseases and conditions. Most ultrasound examinations are done using a sonar device outside of your body, though some ultrasound examinations involve placing a device inside your body. You may need to undergo an ultrasound for a variety of reasons. Ultrasound may be used, among other things, to evaluate a fetus during pregnancy, diagnose gallbladder disease, evaluate flow in blood vessels, guide a needle biopsy, guide the biopsy and treatment of a tumor, study your heart, diagnose some forms of infection or cancer, reveal abnormalities in the scrotum and prostate, and evaluate abnormalities of the muscles and tendons.